Synopsis
The Unity Linux host is missing one or more security updates.
Description
The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-143095 advisory.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry
New test case fails unexpectedly when avx2 matching functions are used.
The test first loads a ranomly generated pipapo set with 'ipv4 . port' key, i.e. nft -f foo.
This works. Then, it reloads the set after a flush:
(echo flush set t s; cat foo) | nft -f -
This is expected to work, because its the same set after all and it was already loaded once.
But with avx2, this fails: nft reports a clashing element.
The reported clash is of following form:
We successfully re-inserted a . b c . d
Then we try to insert a . d
avx2 finds the already existing a . d, which (due to 'flush set') is marked as invalid in the new generation. It skips the element and moves to next.
Due to incorrect masking, the skip-step finds the next matching element *only considering the first field*,
i.e. we return the already reinserted a . b, even though the last field is different and the entry should not have been matched.
No such error is reported for the generic c implementation (no avx2) or when the last field has to use the 'nft_pipapo_avx2_lookup_slow' fallback.
Bisection points to 7711f4bb4b36 (netfilter: nft_set_pipapo: fix range overlap detection) but that fix merely uncovers this bug.
Before this commit, the wrong element is returned, but erronously reported as a full, identical duplicate.
The root-cause is too early return in the avx2 match functions.
When we process the last field, we should continue to process data until the entire input size has been consumed to make sure no stale bits remain in the map.
Tenable has extracted the preceding description block directly from the Unity Linux security advisory.
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.
Solution
Update the affected kernel package.
Plugin Details
File Name: unity_linux_UTSA-2026-143095.nasl
Supported Sensors: Nessus
Risk Information
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:P
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
Required KB Items: Host/local_checks_enabled, Host/cpu, Host/UOS-Server/release, Host/UOS-Server/rpm-list
Exploit Ease: No known exploits are available
Patch Publication Date: 10/23/2026
Vulnerability Publication Date: 5/6/2026